Programming

I write Python code each day, for personal and professional projects.
As I am working on multiple Python projects, old and fresh ones, I have to use different Python versions for those projects, from 2.7.2 to 3.7.0.
Also, I want to switch the Python version of my projects very easily and quickly, in case of we have to upgrade the Python version of the software.
I am a macOS user, and I use a lot HomeBrew.